A case of aplastic anemia associated with letrozole therapy in a patient with breast cancer

An oncological treatment challenge

Abstract

Introduction: aplastic anemia is a rare hematological disorder characterized by bone marrow failure, resulting in pancytopenia with hypoplasia/aplasia due to the loss of hematopoietic stem cells. Approximately 70-80% of the cases are idiopathic, and the rest are mainly hereditary syndromes. An abnormal complete blood count generally arouses suspicion, and a bone marrow biopsy is required to confirm the diagnosis. This report presents the first case of aplastic anemia secondary to the use of letrozole.

Case presentation: We present the case of a 56-year-old female Venezuelan patient diagnosed with aplastic anemia during breast cancer treatment. After first- and second-line treatment, letrozole was administered as maintenance therapy. It was discontinued due to a suspected association with severe, persistent thrombocytopenia in the patient. A bone marrow biopsy confirmed the diagnosis of aplastic anemia. She was treated for both the breast cancer as well as the aplastic anemia, until she ultimately died due to breast cancer progression, seven years after being diagnosed with aplastic anemia.

Conclusions: Aplastic anemia is a rare hematological disorder, and its association with cancer treatment is often due to the toxicity caused by the different medications. This is a challenge for physicians in terms of selecting the proper treatment for oncological disease. This case presents a patient diagnosed with aplastic anemia during breast cancer treatment, emphasizing the importance of monitoring blood counts and recognizing possible complications associated with the use of chemotherapy.